SELECT DISTINCT column1, column2, ... FROM original_table; TRUNCATE original_table; RENAME TABLE new_table TO original_table; END // DELIMITER ; 您可以通过调用存储过程来执行此操作: CALL remove_duplicates(); 这将创建一个新表new_table,将不重复的记录插入到该表中,然后清空原始表original_table,...
Add Unique Index on your table: ALTER IGNORE TABLE `TableA` ADD UNIQUE INDEX (`member_id`, `quiz_num`, `question_num`, `answer_num`); OR Add primry key in your table then you can easilyremove duplicatesfrom your table using below query: DELETE FROM member WHERE id IN (SELECT * FR...
CREATE TABLE temp_students AS SELECT * FROM students; 2) 向临时表中插入不重复的数据: INSERT INTO temp_students SELECT DISTINCT * FROM students; 3) 删除原表: DROP TABLE students; 4) 将临时表重命名为原表名: RENAME TABLE temp_students TO students; 3、使用GROUP BY和HAVING子句 我们可以使用GRO...
DELETE t1 FROM table_name t1 JOIN table_name t2 WHERE t1.id > t2.id AND t1.column1 = t2.column1 AND t1.column2 = t2.column2; -- 创建唯一索引 CREATE UNIQUE INDEX index_name ON table_name (column1, column2, ...); END // DELIMITER ; -- 调用存储过程 CALL remove_duplicates()...
DELIMITER//CREATEPROCEDUREsplit_and_remove_duplicates()BEGINSELECTDISTINCTSUBSTRING_INDEX(SUBSTRING_INDEX(data,',',numbers.n),',',-1)dataFROMtest_tableJOINnumbersONCHAR_LENGTH(data)-CHAR_LENGTH(REPLACE(data,',',''))>=n-1GROUPBYdata;END// ...
CREATE PROCEDURE remove_duplicates() BEGIN -- 创建临时表temp_table用于存储分割后的子串 CREATE TEMPORARY TABLE temp_table( sub_str VARCHAR(255) );-- 将分割后的子串插入到临时表中,假设表名为split_result INSERT INTO temp_table(sub_str)
然后递增 ii,接着我们将再次重复相同的过程,直到 jj 到达数组的末尾为止。...return len(nums) Remove Duplicates from Sorted Array II 题目大意在 Remove Duplicates from Sorted Array(从一个有序的数组中去除重复的数字...,返回处理后的数组长度) 的基础上,可以使每个数字最多重复一次,也就是说如果某一个...
为了将整个锁获取过程做成原子的,要么全部获取到,要么一个都不获取,来避免死锁问题,我们将表级别的 MDL 和分区级别的进行打包排序(顺序保证 TABLE 级别的会优先获取)后统一获取。 未指定分区的语句 在实际的用户场景中,更常见的还是将分区表当作普通表来使用,直接使用不指定分区的普通 DML,例如SELECT * FROM tr ...
I have table with 7 columns where I want to combine three column and want to remove duplicates. Your help will be appreciated. SELECT warranty_indicator, account, date_sold, COUNT(*) AS CNT FROM SERIAL_NUMBERS GROUP BY warranty_indicator, account, date_sold HAVING COUNT(*) >...
I have 2 tables, as all the data seems too large for one (got error on import). I am trying to find if data (let's say rows) duplicate in Table 1 first and remove them. Then I want to see if Table 2 duplicates any of Table 1's rows and remove them from Table 2. Then I ...